1U6B

CRYSTAL STRUCTURE OF A SELF-SPLICING GROUP I INTRON WITH BOTH EXONS

Replaces:  1T42

Summary for 1U6B

• Entry DOI: 10.2210/pdb1u6b/pdb
• Descriptor: 197-MER, 5'-R(*AP*AP*GP*CP*CP*AP*CP*AP*CP*AP*AP*AP*CP*CP*AP*GP*AP*CP*GP *GP*CP*C)-3', 5'-R(*CP*AP*(5MU))-3', ... (7 entities in total)
• Functional Keywords: intron, exon, ribozyme, group i, u1a, rna, structural protein-rna complex, structural protein/rna
• Biological source: Homo sapiens (human); More
• Cellular location: Nucleus: P09012
• Total number of polymer chains: 4
• Total formula weight: 83863.77

Authors

Adams, P.L.,Stahley, M.R.,Kosek, A.B.,Wang, J.,Strobel, S.A. (deposition date: 2004-07-29, release date: 2004-08-10, Last modification date: 2024-02-14)

Primary citation

Adams, P.L.,Stahley, M.R.,Kosek, A.B.,Wang, J.,Strobel, S.A.
Crystal Structure of a Self-Splicing Group I Intron with Both Exons.
Nature, 430:45-50, 2004

PubMed Abstract: The discovery of the RNA self-splicing group I intron provided the first demonstration that not all enzymes are proteins. Here we report the X-ray crystal structure (3.1-A resolution) of a complete group I bacterial intron in complex with both the 5'- and the 3'-exons. This complex corresponds to the splicing intermediate before the exon ligation step. It reveals how the intron uses structurally unprecedented RNA motifs to select the 5'- and 3'-splice sites. The 5'-exon's 3'-OH is positioned for inline nucleophilic attack on the conformationally constrained scissile phosphate at the intron-3'-exon junction. Six phosphates from three disparate RNA strands converge to coordinate two metal ions that are asymmetrically positioned on opposing sides of the reactive phosphate. This structure represents the first splicing complex to include a complete intron, both exons and an organized active site occupied with metal ions.

PubMed: 15175762
DOI: 10.1038/nature02642

Experimental method

X-RAY DIFFRACTION (3.1 Å)